I try not to listen to a song over and over for days because I can burn out on it and never want to hear it again.
But here are some good candidates.: 10.Counting bodies like sheep to the rhythm of the war drums - YouTube Disturbed The Animal lyrics - YouTube http://youtu.be/gyInUMLmZ0s
This I can actually sleep to, I used to study to it, listening to it for solid hours on repeat. Dont ask how.
Apparently I have a thing for strange sounds.